The use of vacuum to lift objects is well known. Vacuum lift attachments for heavy machinery such as excavators are widely used for lifting heavy objects in the construction industry such as concrete, granite slabs, metal sheet and the like. Vacuum lift attachments are also used to lift pipes in pipeline construction. The vacuum lift attachments are fully self-contained with an on-board diesel engine with fuel tank to power an on-board vacuum pump with a vacuum pad or shoe. They are controlled either by a battery operated remote control or a hardwired control fitted inside an excavator or other work machine cabin.
The vacuum lift attachments have a yoke for fitting to an end of an excavator stick. Generally the yokes are manufactured for fitting to a specific excavator size, although multi excavator yokes are available.
Generally a hydraulic rotator is mounted between the yoke and the lift attachment for rotation of the attachment. The rotator is powered by an excavator's auxiliary hydraulic system.
It is considered desirable in the construction, pipe-laying, and related industries to reduce costs and increase safety. To this end, there have been many developments and improvements in the vacuum attachment lifting industry with respect to improving on the existing yoke design, safety features, remote control features, shoe/pad design, engine/pump designs and the like.
In the present specification and claims the term “comprising” shall be understood to have a broad meaning similar to the term “including” and will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. This definition also applies to variations on the term “comprising” such as “comprise” and “comprises”.